Vibratory screeds are frequently employed to impart vibrations to poured concrete for tamping and leveling of the concrete as it is finished. The screed eliminates the tedious manual labor involved in finishing the concrete and therby increases productivity in laying of the concrete as well as improving the quality of the finished concrete slab by providing more accurately controlled slab surfaces as well as controlling the crown.
In addition, the uniform vibratory action that is achieved by a screed will increase the concrete density and load bearing capacity of the finished slab.
It is desirable that a screed be light in weight and formed in sections so that the length of the screed can be readily changed to meet the dimensions of the slab. In the past, the screeds have generally been formed with a truss like construction in which light weight metal braces are arranged in a truss-like pattern to support the screed plates.
U.S. Pat. No. 4,340,351 discloses a vibratory concrete screed composed of a series of parallel, generally triangular, frame members. The corners of the triangular frame members are connected to the screed plates and a ridge tube is connected across the upper ends of the frame members. In the aforementioned patent, diagonal braces are connected between adjacent parallel frame members.